function context() {
	this.mode = 1;
	this.sk = new Array(32);
	this.isPadding = true;
}

//byte转long
function GET_ULONG_BE(b, i) {
	let n = ((b[i] & 0xff) << 24) | ((b[i + 1] & 0xff) << 16) | ((b[i + 2] & 0xff) << 8) | (b[i + 3] & 0xff);
	return n;
}

//long转byte
function PUT_ULONG_BE(n, b, i) {
	b[i] = 0xff & (n >> 24);
	b[i + 1] = 0xff & (n >> 16);
	b[i + 2] = 0xff & (n >> 8);
	b[i + 3] = 0xff & n;
}

//左移n
function SHL(x, n) {
	return x << n;
}

//循环左移n
function ROTL(x, n) {
	return SHL(x, n) | (x >> (32 - n));
}

//交换sk的i位和31-i位
function SWAP(sk, i) {
	t = sk[i];
	sk[i] = sk[31 - i];
	sk[31 - i] = t;
}

let sboxTable = [
	0xd6, 0x90, 0xe9, 0xfe, 0xcc, 0xe1, 0x3d, 0xb7, 0x16, 0xb6, 0x14, 0xc2, 0x28, 0xfb, 0x2c, 0x05, 0x2b, 0x67, 0x9a, 0x76, 0x2a,
	0xbe, 0x04, 0xc3, 0xaa, 0x44, 0x13, 0x26, 0x49, 0x86, 0x06, 0x99, 0x9c, 0x42, 0x50, 0xf4, 0x91, 0xef, 0x98, 0x7a, 0x33, 0x54,
	0x0b, 0x43, 0xed, 0xcf, 0xac, 0x62, 0xe4, 0xb3, 0x1c, 0xa9, 0xc9, 0x08, 0xe8, 0x95, 0x80, 0xdf, 0x94, 0xfa, 0x75, 0x8f, 0x3f,
	0xa6, 0x47, 0x07, 0xa7, 0xfc, 0xf3, 0x73, 0x17, 0xba, 0x83, 0x59, 0x3c, 0x19, 0xe6, 0x85, 0x4f, 0xa8, 0x68, 0x6b, 0x81, 0xb2,
	0x71, 0x64, 0xda, 0x8b, 0xf8, 0xeb, 0x0f, 0x4b, 0x70, 0x56, 0x9d, 0x35, 0x1e, 0x24, 0x0e, 0x5e, 0x63, 0x58, 0xd1, 0xa2, 0x25,
	0x22, 0x7c, 0x3b, 0x01, 0x21, 0x78, 0x87, 0xd4, 0x00, 0x46, 0x57, 0x9f, 0xd3, 0x27, 0x52, 0x4c, 0x36, 0x02, 0xe7, 0xa0, 0xc4,
	0xc8, 0x9e, 0xea, 0xbf, 0x8a, 0xd2, 0x40, 0xc7, 0x38, 0xb5, 0xa3, 0xf7, 0xf2, 0xce, 0xf9, 0x61, 0x15, 0xa1, 0xe0, 0xae, 0x5d,
	0xa4, 0x9b, 0x34, 0x1a, 0x55, 0xad, 0x93, 0x32, 0x30, 0xf5, 0x8c, 0xb1, 0xe3, 0x1d, 0xf6, 0xe2, 0x2e, 0x82, 0x66, 0xca, 0x60,
	0xc0, 0x29, 0x23, 0xab, 0x0d, 0x53, 0x4e, 0x6f, 0xd5, 0xdb, 0x37, 0x45, 0xde, 0xfd, 0x8e, 0x2f, 0x03, 0xff, 0x6a, 0x72, 0x6d,
	0x6c, 0x5b, 0x51, 0x8d, 0x1b, 0xaf, 0x92, 0xbb, 0xdd, 0xbc, 0x7f, 0x11, 0xd9, 0x5c, 0x41, 0x1f, 0x10, 0x5a, 0xd8, 0x0a, 0xc1,
	0x31, 0x88, 0xa5, 0xcd, 0x7b, 0xbd, 0x2d, 0x74, 0xd0, 0x12, 0xb8, 0xe5, 0xb4, 0xb0, 0x89, 0x69, 0x97, 0x4a, 0x0c, 0x96, 0x77,
	0x7e, 0x65, 0xb9, 0xf1, 0x09, 0xc5, 0x6e, 0xc6, 0x84, 0x18, 0xf0, 0x7d, 0xec, 0x3a, 0xdc, 0x4d, 0x20, 0x79, 0xee, 0x5f, 0x3e,
	0xd7, 0xcb, 0x39, 0x48
];

let CK = [
	0x00070e15, 0x1c232a31, 0x383f464d, 0x545b6269, 0x70777e85, 0x8c939aa1, 0xa8afb6bd, 0xc4cbd2d9, 0xe0e7eef5, 0xfc030a11,
	0x181f262d, 0x343b4249, 0x50575e65, 0x6c737a81, 0x888f969d, 0xa4abb2b9, 0xc0c7ced5, 0xdce3eaf1, 0xf8ff060d, 0x141b2229,
	0x30373e45, 0x4c535a61, 0x686f767d, 0x848b9299, 0xa0a7aeb5, 0xbcc3cad1, 0xd8dfe6ed, 0xf4fb0209, 0x10171e25, 0x2c333a41,
	0x484f565d, 0x646b7279
];

let FK = [0xa3b1bac6, 0x56aa3350, 0x677d9197, 0xb27022dc];

//8比特的s盒变换
function sm4Sbox(inch) {
	let i = inch & 0xff;
	let retVal = sboxTable[i];
	return retVal;
}

//算法Lt(.)
function sm4Lt(ka) {
	let bb = 0;
	let c = 0;
	let a = new Array(4);
	let b = new Array(4);
	PUT_ULONG_BE(ka, a, 0);
	b[0] = sm4Sbox(a[0]);
	b[1] = sm4Sbox(a[1]);
	b[2] = sm4Sbox(a[2]);
	b[3] = sm4Sbox(a[3]);
	bb = GET_ULONG_BE(b, 0);
	c = bb ^ ROTL(bb, 2) ^ ROTL(bb, 10) ^ ROTL(bb, 18) ^ ROTL(bb, 24);
	return c;
}

//算法F()，即一轮变换
function sm4F(x0, x1, x2, x3, rk) {
	return x0 ^ sm4Lt(x1 ^ x2 ^ x3 ^ rk);
}

function sm4CalciRK(ka) {
	let bb = 0;
	let rk = 0;
	let a = new Array(4);
	let b = new Array(4);
	PUT_ULONG_BE(ka, a, 0);
	b[0] = sm4Sbox(a[0]);
	b[1] = sm4Sbox(a[1]);
	b[2] = sm4Sbox(a[2]);
	b[3] = sm4Sbox(a[3]);
	bb = GET_ULONG_BE(b, 0);
	rk = bb ^ ROTL(bb, 13) ^ ROTL(bb, 23);
	return rk;
}

//轮密钥生成
function sm4_setkey(SK, key) {
	let MK = new Array(4);
	let k = new Array(36);
	let i = 0;
	// alert("aaa")
	MK[0] = GET_ULONG_BE(key, 0);
	MK[1] = GET_ULONG_BE(key, 4);
	MK[2] = GET_ULONG_BE(key, 8);
	MK[3] = GET_ULONG_BE(key, 12);
	k[0] = MK[0] ^ FK[0];
	k[1] = MK[1] ^ FK[1];
	k[2] = MK[2] ^ FK[2];
	k[3] = MK[3] ^ FK[3];
	for (; i < 32; i++) {
		k[i + 4] = k[i] ^ sm4CalciRK(k[i + 1] ^ k[i + 2] ^ k[i + 3] ^ CK[i]);
		SK[i] = k[i + 4];
	}
	// alert("SK:"+SK.length+" "+SK[0])
}

//
function sm4_rounds(sk, input, output) {
	let i = 0;
	let ulbuf = new Array(36);
	ulbuf[0] = GET_ULONG_BE(input, 0);
	ulbuf[1] = GET_ULONG_BE(input, 4);
	ulbuf[2] = GET_ULONG_BE(input, 8);
	ulbuf[3] = GET_ULONG_BE(input, 12);
	while (i < 32) {
		ulbuf[i + 4] = sm4F(ulbuf[i], ulbuf[i + 1], ulbuf[i + 2], ulbuf[i + 3], sk[i]);
		i++;
	}
	PUT_ULONG_BE(ulbuf[35], output, 0);
	PUT_ULONG_BE(ulbuf[34], output, 4);
	PUT_ULONG_BE(ulbuf[33], output, 8);
	PUT_ULONG_BE(ulbuf[32], output, 12);
}

function padding(input, mode) {
	if (input == undefined) {
		return null;
	}

	let ret = [];

	ret = ret.concat(input);
	if (mode == 1) {
		var p = 16 - (input.length % 16);
		for (let i = 0; i < p; i++) {
			ret[input.length + i] = p;
		}
	} else {
		var p = input[input.length - 1];
		for (let t = 0; t < p; t++) {
			ret.pop();
		}
	}
	return ret;
}

//生成加密密钥
function sm4_setkey_enc(ctx, key) {
	if (ctx == undefined) {
		Error("ctx is null!");
	}

	if (key == undefined || key.length != 16) {
		Error("key error!");
	}
	// alert("ctx"+ctx.sk.length);
	ctx.mode = 1;
	sm4_setkey(ctx.sk, key);
}

//生成解密密钥
function sm4_setkey_dec(ctx, key) {
	if (ctx == null) {
		Error("ctx is null!");
	}

	if (key == null || key.length != 16) {
		Error("key error!");
	}

	let i = 0;
	ctx.mode = 0;
	sm4_setkey(ctx.sk, key);
	ctx.sk = ctx.sk.reverse();
}

function sm4_crypt_ecb(ctx, input) {
	// alert("input"+input[0]+input[1]);
	// alert("input-size"+input.length);
	if ((input == null) | (input == "")) {
		Error("input is null!");
	}
	if (ctx.isPadding && ctx.mode == 1) {
		input = padding(input, 1);
	}
	// alert("input-size"+input.length)
	let length = input.length;
	let bous = [];
	for (let t = 0; t < length; t += 16) {
		let inn = [];
		let out = [];
		inn.push(
			input[t + 0],
			input[t + 1],
			input[t + 2],
			input[t + 3],
			input[t + 4],
			input[t + 5],
			input[t + 6],
			input[t + 7],
			input[t + 8],
			input[t + 9],
			input[t + 10],
			input[t + 11],
			input[t + 12],
			input[t + 13],
			input[t + 14],
			input[t + 15]
		);
		// alert("inn-size"+inn.length);
		sm4_rounds(ctx.sk, inn, out);
		// alert("out-size"+out.length)
		bous = bous.concat(out);
	}

	// alert("bous-size"+bous.length);
	if (ctx.isPadding && ctx.mode == 0) {
		bous = padding(bous, 0);
	}
	return bous;
}
// module.exports = {
//     context, sm4_setkey_enc, sm4_crypt_ecb, sm4_setkey_dec
// }
export default { context, sm4_setkey_enc, sm4_crypt_ecb, sm4_setkey_dec };
